The present invention relates to a composite semiconductor device such as an LED (Light Emitting Diode) array manufactured by dicing, and also relates to a print head and an image forming apparatus using the composite semiconductor device.
The composite semiconductor devices are manufactured by forming a plurality of semiconductor elements on device-forming areas of a semiconductor wafer, and by dicing the semiconductor wafer at dicing areas (between the device-forming areas) to divide the semiconductor wafer into a plurality of semiconductor chips (i.e., composite semiconductor devices).
Generally, a dicing blade that rotates at a high speed is used to divide the semiconductor wafer. When the semiconductor wafer is diced using the dicing blade, cracks or chipping may be generated on the semiconductor chips due to an external force applied by the dicing blade.
In order to prevent generation of cracks and chipping on the semiconductor chips and to thereby enhance yield rate, it is proposed to provide separate pattern portions in the dicing areas of the semiconductor wafer for preventing propagation of the force to the device-forming areas in the dicing process (see, Japanese Laid-Open Patent Publication No. 2008-010571).
Recently, in accordance with downsizing and upgrading of the semiconductor devices, a high precision dicing process has been employed. In the high precision dicing process, the semiconductor wafer is diced at a position in the close vicinity of the device-forming areas. In such a case, the effect of the separate pattern portions decreases, and cracks may be generated on the semiconductor chips. Therefore, it is demanded to prevent generation of cracks on the semiconductor chips (i.e., composite semiconductor devices) even in a high precision dicing process.